Reports from Vienna Saturday say U.S. officials have warned members of the International Atomic Energy Agency that North Korea appears to be ready to conduct an underground nuclear test in the near future.
The reports say a test explosion of a small-scale nuclear device using plutonium could take place as soon as June.
Diplomats tell reporters that U.S. officials have supplied satellite photographs of activity in North Korea to support their argument that North Korea is planning a controlled nuclear explosion.
Neither the IAEA nor the United States has commented officially on Saturday's reports. However, U.S. Assistant Secretary of State Christopher Hill told reporters in South Korea Friday that the Communist North's plutonium reactor at Yongbyon has been shut down for close to three weeks. The North Koreans' move raised suspicions that an operation may be under way to reprocess nuclear fuel into material suitable for use in a nuclear warhead.
Authorities in Seoul have warned North Korea that a nuclear test would isolate Pyongyang from the international community even further, and would endanger its future.
Some information for this report provided by AP and Reuters.